Clinical Neurology and Neurosurgery 114 (2012) 316–320 Contents lists available at SciVerse ScienceDirect Clinical Neurology and Neurosurgery j o ur nal homep age: www.elsevier.com/locate/clineuro Preliminary findings of the effects of autonomic dysfunction on functional outcome after acute ischemic stroke Li Xiong, Howan Leung, Xiang Yan Chen, Jing Hao Han, Thomas Leung, Yannie Soo, Eddie Wong, Anne Chan, Alexander Lau, Ka Sing Wong ∗ Department of Medicine & Therapeutics, Chinese University of Hong Kong, Hong Kong, China a r t i c l e i n f o Article history: Received 20 May 2011 Received in revised form 24 October 2011 Accepted 24 October 2011 Available online 15 November 2011 Keywords: Ischemic Stroke Autonomic dysfunction Outcome a b s t r a c t Background and purpose: Impaired autonomic function is common in the acute poststroke phase but little is known about its effects on functional outcome after acute ischemic stroke. This study sought to inves- tigate the impact of autonomic dysfunction by Ewing’s classification on functional outcome 2 months after acute ischemic stroke. Methods: 34 consecutive acute ischemic stroke patients within 7 days after onset were enrolled. On admis- sion, autonomic function was assessed by Ewing’s battery tests. Stroke severity was assessed by the National Institutes of Health Stroke Scale (NIHSS), autonomy in activities of daily living by the Barthel Index (BI), and global disability by the modified Rankin Scale (mRS). BI and mRS were also evaluated 2 months after ischemic stroke onset. Results: On admission, eight patients were diagnosed as minor autonomic dysfunction and 26 patients as relatively severe autonomic dysfunction. The prevalence of relatively severe autonomic dysfunction in ischemic stroke patients was 76.5%. There were no significant differences in baseline characteristics between the minor and severe autonomic dysfunction groups. 2 months after stroke onset, the mean BI score of patients with minor autonomic dysfunction and severe autonomic dysfunction increased from 76.3 ± 15.3 on admission to 95.0 ± 7.1, 66.5 ± 15.2 on admission to 74.8 ± 15.9 respectively. The mean BI score after 2-month stroke onset and the change in BI from admission to 2-month outcome (delta BI) in patients with severe autonomic dysfunction were lower than those in patients with minor autonomic dysfunction (all P < 0.05). Conclusions: Autonomic dysfunction occurs in acute stroke patients. Relatively severe autonomic dys- function is related to an unfavorable functional outcome in patients with acute ischemic stroke. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Initial severity of stroke and age are currently considered the most powerful predictors of functional recovery and eventual home discharge of ischemic stroke survivors [1,2]. However, studies have showed that ischemic stroke is associated with impairment of car- diac autonomic function [3,4]. Both a reduced heart rate variability (HRV) and an impaired cardiac baroreceptor sensitivity (BRS) have been identified to be associated with adverse clinical outcomes after the acute phase of ischemic stroke [5–7]. Recently, Sykora et al. [8] showed reduced BRS compromised autonomic adjustment of heart rate (HR) and vascular tone to sudden blood pressure (BP) changes in acute and subacute stroke patients. They concluded that sympathetic overactivity and blunted BRS predict poor prognosis after stroke [9,10]. Thus, early diagnosis of autonomic dysfunction ∗ Corresponding author. Tel.: +852 2632 3144; fax: +852 2649 3761. E-mail address: ks-wong@cuhk.edu.hk (K.S. Wong). has prognostic and therapeutic implications in acute stroke. Hilz et al. reported stroke severity assessed by National Institutes of Health Stroke Scale (NIHSS) scores correlates with autonomic dys- function and can be used as premonitory signs of autonomic failure [11]. Till date, the relative impact of cardiac autonomic impairment on functional outcome after acute ischemic stroke has not been fully clarified. Accordingly, this prospective study was designed and undertaken to assess the impact of cardiac autonomic dysfunc- tion by Ewing’s autonomic function tests on functional outcome 2 months after acute ischemic stroke. 2. Methods 2.1. Subjects Consecutive acute ischemic stroke patients within 7 days after onset were enrolled in Prince of Wales Hospital in Hong Kong between January 2007 and April 2009. Patients were included in the study only if they fulfilled all the following criteria: (1) 0303-8467/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.clineuro.2011.10.037